Making of Apple Cider

CIDER MAKING

Cider is an alcoholic beverages made from fermented apple juice (at least in the context of England). In the US, however, ‘cider’ meant rough apple juice while ‘hard cider’ is the fermented stuff.

There are many names to cider. In France, it’s cidre. In Spain, it’s sidra. In German, it’s apfelwein. In fact, the word 'cider' itself is supposed to be derived from Greek or even Hebrew sources and simply means 'strong drink'. Even though they are all quite different, they are all based on apples!

Various different types of apples are needed to make good blended cider. Though opinions differ, the apples used in cider making are generally closely related to crab apples than ordinary eating apples (dessert apples) and have higher tannin content. These are mainly the ‘bittersweet’ and ‘bittersharp’ varieties of apples. The table below gives the approximate composition for an ideal cider apple juice, compared with other varieties of juices.

The Composition of Apple Juice [Figures in percent by weight]
Component	Bramley	Cox	Typical bittersweet	Ideal cider apple
Sugar	10	12	15	15
Malic acid	> 1	0.5	< 0.2	0.4
Tannin	< 0.05	0.1	> 0.2	0.2
Amino nitrogen	0 - 300 parts per million depending on cultivation
Starch	0 - 2%, depending on fruit maturity
Pectin	0 - 1%, depending on fruit storage period

Figure taken from http://ourworld.compuserve.com/homepages/andrew_lea/Part2.htm

Generally steps involved in apple cider making are outlined in the flowchart below.

ACIDITY and pH

Acidity plays quite an important role in the cider making process but it is controlled mainly by the varieties of apples rather than climate. It has 2 aspects – total acid and pH. Total acid is related to the perception of acid flavour while pH is related to various aspects of the fermentation biochemistry. Usually, for cider juice, the acid content is about 0.3 – 0.5%. If the total acid is too low, the pH will be too high and the fermentation will be susceptible to bacterial infections. If the total acid is too high, the pH will be low enough to safeguard against infection but the final cider will be unacceptably sharp to the palate and may never be pleasant to drink. Acidity is measured by titration while pH is measured using a pH meter.

SULPHUR DIOXIDE

Sulphurdioxide or SO₂ or metabisulphite (all the same thing) is added to the apple cider. Its main function is to inhibit the growth of spoilage yeasts and bacteria, while allowing desirable fermenting yeasts (such as Saccharomyces cerevisiae or uvarum) to multiply and dominate the conversion to alcohol. Only a small amount is used and its effective depends on pH of the juice (see the table below).

Addition of Sulphur Dioxide
Juice pH	SO2 needed in parts per million (ppm)	Campden Tablets per gallon or ml. of 5% SO2 stock solution per litre
Above 3.8 (insipid)	.....Lower pH to 3.8 with addition of malic acid.....
3.8 - 3.5	150	3
3.5 - 3.3 (balanced)	100	2
3.3 - 3.0	50	1
Below 3.0 (sharp)	None	None

Figure taken from http://ourworld.compuserve.com/homepages/andrew_lea/Part3.htm

There are concerns regarding the excessive use of sulphur dioxide. Even though few people are hypersensitive to it in its free state, no sulphur dioxide must remain free by the end of fermentation, since it becomes bound to various intermediate chemicals (principally acetaldehyde) which the yeast produces on its route from sugar to alcohol.

Below describes some of the types of apple cider that could be made and their differences.

------------------------------------------------

DRY CARBONATED CIDER

------------------------------------------------

Dry ciders are those which have been left to ferment to maturation. Almost all the sugars in the original juices are fermented. Only a small amount are not unfermented which gives the cider its residual sweetness.

To get dry carbonated cider, we need to incorporate excess carbon dioxide under pressure into the cider and bottled them. Commercially, this is done by chilling the cider and dissolving 2 or 3 volumes of carbon dioxide in the liquid cider using some special equipment. However, fermentation itself can generate the carbon dioxide by ‘natural conditioning’. One way is by racking and bottling the fermentation at an early stage, allowing the cider fermentation to complete and mature in the bottle. The carbon dioxide produced will be dissolved in the cider and produces bubble upon opening of the bottles. A disadvantage of this technique is that the yeast deposit in the bottle may be rather heavy and coarsely flavoured. Another way to overcome this problem is to bottle the cider after fermentation to dryness, and adding a small amount of priming sugar to allow secondary yeast fermentation of the sugar to produce the gas.

A note to the type of bottles used to bottle carbonated cider: the bottles used must be able to withstand the pressure generated by the gas. Nowadays, the PET (polyethyleneterephthalate) bottles are widely used since it is light-weight and holds moderate pressure reasonably well. Moreover, it is of lower risk of than using glass bottles.

------------------------------------------

SWEET APPLE CIDER

------------------------------------------

Sweet apple cider, by its name, is much sweeter due to the presence of either unfermented or added sugar. There is usually a risk of re-fermentation if any yeast is still present. Commercially, this problem can be solved by centrifugation and filtration of dry cider to remove most of the yeast, followed by pasteurisation to eliminate any remaining yeast after the addition of sugar.

Images in the flowchart are taken from

The Composition of Apple Juice

[Figures in percent by weight]

Addition of Sulphur Dioxide